My motivation for this little hack, like many other hacks, was not so much the novelty of building one, but avoiding the expense of buying one.
Having a Commodore 64, and not wanting to spend money buying a joystick, I started experimenting with building my own. The joystick pictured here is actually the third one, and the best one I built. To my surprise, it was actually a much better joystick than the ones you could buy, and given a choice, most people preferred to play with this one than with the expensive Wico joysticks.
The reason for this is that the handle is not too hard to push, but doesn't need to be pushed too far. The handle is basically a piece of wood 'screwed' into a piece of a very stiff tensile spring, which is in turn screwed into the bottom of the block. Because the spring is tensioned in such a way that the coils press against each other, it pulls itself to the center quite nicely. The contacts are a series of silver plated contacts from some old and bizarre ferrite core based Olivetti piece of computer equipment that I dismantled years back. These contacts are much better than regular joystick contacts, it turns out. My brother Markus wrote a little Tetris game back around 1990, and developed it using this joystick. The game turned out to be very difficult to play with any other joystick, because my joystick had so little contact bounce that he didn't need to do any debouncing, but with normal joysticks, debouncing was very necessary.
My sister ended up taking the joystick to university some years later, and she and her friends played a lot of games on the Commodore 64. To my surprise, the joystick survived undamaged (even without me being there to fix it), and was the joystick of choice among the people who played games on my sister's computer!